Sculpt: Split original normal into original normal and plane

This allows to create different effects with some brushes that use the sculpt plane.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D5818

4 files changed, 25 insertions, 5 deletions

diff --git a/source/blender/blenloader/intern/versioning_270.c b/source/blender/blenloader/intern/versioning_270.c
index 38c19fc647a..a3dc177262e 100644
--- a/source/blender/blenloader/intern/versioning_270.c
+++ b/source/blender/blenloader/intern/versioning_270.c
@@ -1746,7 +1746,8 @@ void blo_do_versions_270(FileData *fd, Library *UNUSED(lib), Main *bmain)
     if (!DNA_struct_elem_find(fd->filesdna, "Brush", "float", "falloff_angle")) {
       for (Brush *br = bmain->brushes.first; br; br = br->id.next) {
         br->falloff_angle = DEG2RADF(80);
-        br->flag &= ~(BRUSH_FLAG_UNUSED_1 | BRUSH_FLAG_UNUSED_6 | BRUSH_GRAB_ACTIVE_VERTEX |
+        /* These flags are used for new feautres. They are not related to falloff_angle */
+        br->flag &= ~(BRUSH_FLAG_UNUSED_1 | BRUSH_ORIGINAL_PLANE | BRUSH_GRAB_ACTIVE_VERTEX |
                       BRUSH_SCENE_SPACING | BRUSH_FRONTFACE_FALLOFF);
       }
 
diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index f9a7e59c509..dc94da1cedf 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -4247,7 +4247,8 @@ static void calc_sculpt_plane(
 
   if (ss->cache->mirror_symmetry_pass == 0 && ss->cache->radial_symmetry_pass == 0 &&
       ss->cache->tile_pass == 0 &&
-      (ss->cache->first_time || !(brush->flag & BRUSH_ORIGINAL_NORMAL))) {
+      (ss->cache->first_time || !(brush->flag & BRUSH_ORIGINAL_PLANE) ||
+       !(brush->flag & BRUSH_ORIGINAL_NORMAL))) {
     switch (brush->sculpt_plane) {
       case SCULPT_DISP_DIR_VIEW:
         copy_v3_v3(r_area_no, ss->cache->true_view_normal);
@@ -4284,10 +4285,20 @@ static void calc_sculpt_plane(
     }
 
     /* for area normal */
-    copy_v3_v3(ss->cache->sculpt_normal, r_area_no);
+    if ((!ss->cache->first_time) && (brush->flag & BRUSH_ORIGINAL_NORMAL)) {
+      copy_v3_v3(r_area_no, ss->cache->sculpt_normal);
+    }
+    else {
+      copy_v3_v3(ss->cache->sculpt_normal, r_area_no);
+    }
 
     /* for flatten center */
-    copy_v3_v3(ss->cache->last_center, r_area_co);
+    if ((!ss->cache->first_time) && (brush->flag & BRUSH_ORIGINAL_PLANE)) {
+      copy_v3_v3(r_area_co, ss->cache->last_center);
+    }
+    else {
+      copy_v3_v3(ss->cache->last_center, r_area_co);
+    }
   }
   else {
     /* for area normal */
diff --git a/source/blender/makesdna/DNA_brush_types.h b/source/blender/makesdna/DNA_brush_types.h
index a503d3b6739..06e93a3af1f 100644
--- a/source/blender/makesdna/DNA_brush_types.h
+++ b/source/blender/makesdna/DNA_brush_types.h
@@ -406,7 +406,7 @@ typedef enum eBrushFlags {
   BRUSH_SIZE_PRESSURE = (1 << 3),
   BRUSH_JITTER_PRESSURE = (1 << 4),
   BRUSH_SPACING_PRESSURE = (1 << 5),
-  BRUSH_FLAG_UNUSED_6 = (1 << 6), /* cleared */
+  BRUSH_ORIGINAL_PLANE = (1 << 6),
   BRUSH_GRAB_ACTIVE_VERTEX = (1 << 7),
   BRUSH_ANCHORED = (1 << 8),
   BRUSH_DIR_IN = (1 << 9),
diff --git a/source/blender/makesrna/intern/rna_brush.c b/source/blender/makesrna/intern/rna_brush.c
index 716e8526071..6076ab3715f 100644
--- a/source/blender/makesrna/intern/rna_brush.c
+++ b/source/blender/makesrna/intern/rna_brush.c
@@ -1978,6 +1978,14 @@ static void rna_def_brush(BlenderRNA *brna)
                            "When locked keep using normal of surface where stroke was initiated");
   RNA_def_property_update(prop, 0, "rna_Brush_update");
 
+  prop = RNA_def_property(srna, "use_original_plane", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flag", BRUSH_ORIGINAL_PLANE);
+  RNA_def_property_ui_text(
+      prop,
+      "Original Plane",
+      "When locked keep using the plane origin of surface where stroke was initiated");
+  RNA_def_property_update(prop, 0, "rna_Brush_update");
+
   prop = RNA_def_property(srna, "use_automasking_topology", PROP_BOOLEAN, PROP_NONE);
   RNA_def_property_boolean_sdna(prop, NULL, "automasking_flags", BRUSH_AUTOMASKING_TOPOLOGY);
   RNA_def_property_ui_text(prop,